Armored cable



Patented May 25, 1926.

UNITED STAT-Es' PATENT oFFlcE.

GUY v. BUDLoNG ANDALEXANDER o.- noEETMANN, or WORCESTER., MASSACHU- sETTs, AssreNoRs To THE AMERICAN STEEL AND WIRE COMPANY or NEW JER- SEY,`A. CORPORATION 0F NEW JERSEY.

ARMORED CABLE.

Application led September 2, vv1920. Serial No. 407,750.

.This invention relates to the construction of electric cables, and more vparticularly to the construction of cables requirin a protecting armor, such as undergroun aerial, and submarine cables.

One object of our present invention is the construction of cables of the above types having a metallic nonfmagnetic` armor and 'constructed land arranged to permit the use of an exploring coil in localizing breaks or faults, as they are commonly termed, in the cables.

Another object of the invention is the provision of an armored cable having the novel construction, arrangement, and combination of parts and materials illustrated and described,.and specifically pointed out in thel shown in Figure' 1.

Figure 3 is a diagrammatical plan, hereinafter described.

Figure 4 is a plan of an exploring coil and receiver used in detecting -breaks and faults in armored cables. p

In the accompan ing drawings, the numeral 10 designates t e conductors of our improved cable. These conductors 10 may be made of strands instead of single wires, as shown, and the cables may have but a single conductor in lieu of the plurality of conductors shown. The conductors 10.are covered with a layer of insulatory material 11 Whichin turn is covered with tape or braid 12, and' tallic non-magnetic armor, this armor pref-4 erably being formed of two layers of helical ly wound strips of zinc 15 and 16, the outer layer 16 being staggered with respect to the inner layer 15, so as to overlap the helical joint formed by the abutting edges of the strip 15. The zinc strips 15 and 16 forming the metallic non-magnetic armor isenclosedl within an external covering made of any suitable material and made lwater-proof or fire-proof, or both, in any desired known manner.

With cables made'\in this manner any breaks or faults in a cable may be easily and quickly localized by the use of a suitable detector, without the necessity of removing the defective ,cable from the ground, and with a minimum amount of excavation.

ln determining thel location of a fault or break in arcable, a detector such as is shown in Figures 3 and 4 will be employed, this detector comprising an exploring coil 18 con'- nected by wires 19 and y20 to a telephone receiver 21. (See Figure 4.)

In localizmg a fault or kbreak in avcable embodying ourinvention, a point 22 on one conductor 10 willbc connected to one end of a connection 23, and an adjacent lpoint 29 in a second conductor 10 willv be connected to a connection 28. The connection 23 is attached by one end to asource of intermittent current 24, this -source also being attached to one end of a connection 25. The other end of the connection 25 is attached to a commutator `or. make and break switch 26, the current source4 24 and make and break switch 26 being mounted on a Vsuitable connecting shaftor rod 27. The

make and' breakswitch 26 is secured to one' end o f the connection 28 lwhich has its other end connected at the point 29 to one of the cableconductors 10, as 4has been described.

From the foregoing it will be readily seen an intermittentcurrent is supplied which passes along the conductors 10 of the cable, and which may be detected byl means of the portable explorin coil 18 and receiver 21.f In using this etector the operator carries the coil 18 and receiver 21 along the path ofthe cable, which may be submerged or may be buried in a trench, and which due to its metallic non-magnetic armor, allows causes abuzz in the telephone receiver 21 Vwhich will continue to sounduntil the fault,

(indicated at 30, Figure 3), is reached.

' the magneticlines of force to be communi- 'cated to the core of the magnetically permeable coil 18. The' coil eing permeable 'When such fault is reached an interruption in the cable.

in the magnetic lines of force is caused thereby, and buzzing'in the receiver stops, and thereby indicates to the operator the location of the jfault. The result is not possible with an armor of magnetic material, as the magnetic armor' is magnetically pervmea'iole,` which* causes the magneticvlines of force to be .retained Within said .magnetic armor and renders the coil 18 and receiver 21 inoperative in localiz'ingaults or breaks It will be' seen that our improved cable construction provides a metallic armored cable, whereinfaults may be quickly localized at a minimum expense and Without the necessity of removing anypart of the cable for examination, as 'Will be rcadil understood and appreciated by those sgilled in the art.

Various changes and modifications inthe construction and arrangement of the parts -of the cables made accordingto our invenf' tion', may he made without departing `from the spirit and scope thereof as defined in the appended' claim.

We'claimz- A flexible armored cable comprising a plurality of insulated conductors, a lead sheath mounted around and enclosing said c0nduc`tors,. a fibrous covering for said sheath, a non-.magnetic metallic armor surroundin said fibrous covering, said armor comprising inner and outer helically Wound zinc-strips, said outer strip being staggered with respect to said inner strip so asto overlap'the helical jointformed bythe abutting edges of said inner strip, and a Waterproof coveringV enclosing said armor.

In witness whereof, I have yhereunto signed my name.

GUY V. BUDLONG. inv witness whereof, l have hereunto signed my name.

ALEXANDER 0. HOEFTMANN. 

